Molecular identification and mapping of a novel stripe rust resistance gene in wheat resistance line CH5389

Stripe rust, caused by Puccinia striiformis is one of the most destructive diseases of wheat worldwide. CH5389 is a wheat-Thinopyrum intermedium derived line conferring stripe rust resistance. Genetic analyses of seedlings of F-2 populations and F-2:3 families developed by crossing CH5389 and susceptible common wheat revealed that stripe rust resistance in CH5389 was controlled by a single dominant gene that was designated YrCH5389. Light SSR and EST-PCR polymorphic markers on chromosome 3AL were identified in F-2 population of CH5389/Taichung29. The YrCH5389 was flanked by EST marker BE405348 and SSR marker Xwmc388 on chromosome 3AL with genetic distances of 2.2 and 4.6 cM, respectively. Comparative genomic analysis demonstrated that the orthologous genomic region of YrCH5389 covered 990 kb in rice, 640 kb in Brachypodium, and 890 kb in sorghum. Based on the locations of the markers, the resistance gene was located to chromosome deletion bin 3AL-0.85-1.00. Because there are no officially named stripe rust resistance genes on the 3AL chromosome, the YrCH5389 should be designated as a new resistance gene. These linkage markers could be useful for marker-assisted selection in wheat resistance breeding.